This pattern is worked mainly in sc. It includes intarsia crochet on the bonnet and side windows, but includes a full photo tutorial for those unfamiliar with this technique. Any yarn may be used, as long as all colours are of a similar weight and the hook is selected to give a firm fabric. Using DK yarn and a 3mm hook, my finished digger measured approx 25 cm long. For the digger shown I used:

Yellow: 45g, 100m
Charcoal: 45g, 130m
Grey: 54g, 97m
Silver: 15g, 65m
Metallic: 5g, 12m

It requires stuffing, foam rubber is preferred to keep the shaping correct.